Searching into the meaning of the oracle, they found, first, that Argos belonged to them by right of their being next of kin, for after the death of Eurystheus they were the sole survivors of Perseus' line;Sthenelus, father of Eurystheus, was a son of Perseus. For the manner of Eurystheus' death see Isoc. 4.60. next, that Lacedaemon was theirs by right of gift, for when Tyndareus, having been driven from his throne,Tyndareus, son of Perieres and of Perseus' daughter, Gorgophone, was king of Lacedaemon until driven out by his half-brother Hippocoön and by Hippocoön's sons. See Apollod. 3.10.5. was restored to it by Heracles,Heracles slew Hippocoön and his twenty sons and restored Tyndareus. after Castor and Polydeuces had vanished from among men,Castor was slain during a foray in Messene. His brother, Polydeuces, who according to most accounts was a son of Zeus by Leda, while Castor was a son of Tyndareus by Leda, refused to accept immortality unless it was shared by his brother. Zeus, therefore, granted that the two brothers dwell, on alternate days, among the gods and among men. According to others both were sons of Zeus. Hence Isocrates can refer to their kinship with Heracles, the son of Zeus and Alcmene. See Apollod. 3.11.2 and Isoc. 10.61. he gave the land to Heracles because of this act of kindness and also because of the kinship of Heracles and his own sons;